Hi Paul, Using food scraps as feedstock for the digester is being done and it will be digested like any other organic material. Human 'toilet' waste as feedstock will also generate some biogas, although there are some hygiëne challenges around the biodigester and the effluent coming from it. I have never heard of any issue with pathogens from the gas, especially as it is being burnt eventually.What pathogen issue do you mean exactly?And you mean a safe processing of human waste would change the life of rural Kenyans?Love to hear more,Geert